This study involves patients who have experienced either an in-hospital or out-of-hospital cardiopulmonary arrest, and who meet the 2015 American Heart Association (AHA) inclusion/exclusion criteria for targeted temperature management \[i.e., they are comatose or exhibit no meaningful response to verbal commands with return of spontaneous circulation (ROSC) after cardiac arrest\]. After induction of hypothermia protocol after cardiopulmonary arrest (i.e., targeted temperature management), patients will undergo ocular ultrasound at three time points.
